This invention relates generally to a vehicle alarm system and more specifically to an alarm system which is particularly applicable to school buses and which forces the bus driver to walk to the rear of the bus before it is stored, thereby allowing him or her to detect the presence of any children or other passengers who may remain on the bus.
After unloading all passengers at the end of the day, school buses are normally driven to a storage yard for overnight or over the weekend storage. Bus company policy typically requires the driver to make a "walk-through" examination of the bus to make certain that no passengers inadvertently remain on board the bus. However, drivers do not always follow the prescribed policy, and there have been notable incidents where school children have fallen asleep on the bus and been locked inside of it overnight due to the failure of the driver to notice their presence. Drivers are often anxious to complete their shift and do not take the time to walk through the bus and look for sleeping children or others who may remain on board. If small children are inadvertently locked in a bus overnight or even for a shorter period, the consequences can be severe.
It is thus evident that there is a significant need to force drivers of school buses and other vehicles to walk through the vehicle at the end of the route in order to prevent children from possibly being locked on the bus and subjected to cold, fright and other unpleasant experiences. It is the principal goal of the present invention to provide an alarm system that forces a driver of a school bus or other vehicle to walk to the rear of the vehicle before it is stored at the end of each route.
More specifically, the present invention is directed to an alarm system that generates an audible sound when the ignition of the vehicle is turned off and requires the driver to walk to the rear of the vehicle and operate a switch in order to silence the alarm. By making the driver walk through the bus, the alarm system forces him to check the seats for the presence of any remaining passengers even if he is disinclined to do so.
In accordance with the invention, the audible alarm sound may be generated by the existing horn of the vehicle, and the system also makes use of the existing ignition switch, batter and safety system door switch of the bus. The alarm system includes electrical wiring and components which may take the form of relays that perform various functions. One relay is wired to the ignition so that it is energized whenever the ignition is on in order to interrupt the circuit which activates the horn. Another relay is an arming relay which is wired so that it arms the horn when the door switch of the bus safety system is activated at the first stop or when the red warning lights are energized at the first stop. The arming relay is energized along two different paths, one of which includes a normally closed disable switch located at the rear of the bus and the other of which is provided by a third relay which overrides the disable switch so that the disable switch is only effective to disarm the horn after the ignition has been turned off. The override relay is energized by the first activation of the door switch and remains energized until the ignition is shut off, after which the disable switch can be operated to disarm the horn and silence it.
By virtue of this arrangement, the horn is armed automatically upon initial opening of the door (or initial energization of the warning lights), and the driver cannot keep it from becoming armed or otherwise tamper with it. At the same time, if the safety system of the bus is never activated, the door switch (or warning light system) never acts to arm the alarm and the bus can be driven without passengers and not activate the alarm system at the end of the run.
Once the alarm system has been armed, the alarm will sound as soon as the ignition is turned off. Before the ignition is turned off, the disable switch is ineffective to disarm the alarm system, so the driver cannot defeat the alarm by having the last child to be let off deactivate the system. When the alarm signal sounds, the driver can turn the ignition back to the on position to silence it, but he then must walk through the bus and manually operate the disable switch situated at the rear of the bus before he can turn the ignition key off again without the alarm sounding. This requires him to walk through the bus so that he will notice the presence of any children that may remain on board, either because they have fallen asleep or otherwise.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.